SD is theory and marketing jibberish only, it has proven worthless by the innovation of contemporary construction.
While I feel it could have been stated more clearly, I'm pretty sure he meant "for equal construction." No, even then it doesn't predict perfectly--but nothing else does either.
Just because something doesn't mean
everything, or predict the outcome
perfectly 100% of the time doesn't mean it's worthless. A lot of variables go into the equation and none of them predict everything all by themselves either. That doesn't mean they're worthless--just that there are many variables and no single one is so important you can disregard the rest. If bullet construction meant everything we could hunt Cape Buffalo with 223's and X bullets. Just because that wouldn't be wise doesn't mean bullet construction is also worthless marketing jibberish.
SD isn't "theory" any more than the number you get with a bullet in your caliper or on the scale is. It's a very real physical attribute that does have real meaning. Just
how much meaning for penetration obviously can be and has been overstated in the past. All else is not always equal.
The only time my 300 has failed to exit a deer or antelope was a 130 XBT on an antelope. I'm pretty sure I could live to 100 shooting 180 or 200 X's and never have that happen on a similar shot.
While this thread is about terminal performance, SD is just as important for exterior ballistics since for any shape, a bullet's BC will be directly proportional to its SD.
